Rational Use of Drugs

WHO Definition

The rational use of drugs requires that patients receive medications appropriate to their clinical needs, in doses that meet their own individual requirements for an adequate period of time, and at the and at the lowest cost to them and their community.

  • Medicines play an integral part of healthcare delivery.
  • Irrational use of medicines is a major challenge facing many health systems across the world causing increased morbidity, mortality, cost and drug resistance.
  • WHO estimates that more than half of all medicines are prescribed, dispensed or sold inappropriately, and that half of all patients fail to take them correctly. 

Common errors

  1. Viral infection (common cold) – prescribing antibiotic
  2. Diarrhoea- Ornidazole plus ofloxacin
  3. PPI and H2 blocker – prescribed whether pt has acid reflux or not
  4. Multivitamins – prescribed whether pt has deficiency or not
  5. Using injections where oral drugs would be sufficient.

Aspects of Irrational Drug Use


• Inadequate examination of patient

• Incomplete communication between patient and doctor

• Lack of documented medical history

• Inadequate laboratory Resources


• Extravagant prescribing

• Over-prescribing

• Incorrect prescribing

• Under-prescribing

• Multiple prescribing/ers

• Influence by Pharmaceutical companies – look for evidence produced by MR


• Incorrect interpretation of the prescription

• Retrieval of wrong ingredients

• Inaccurate counting, compounding, or pouring pouring

• Inadequate labeling • Unsanitary procedures

• Packaging: – Poor-quality packaging materials – Odd package size, which may require repackaging – Unappealing package

Patient adherence:

• Poor labeling

• Inadequate verbal instructions

• Inadequate counseling to encourage adherence

• Inadequate follow-up/support of patients

• Treatments or instructions that do not consider the consider the patient’s beliefs, environment, or culture.

Significance of Rational Drug Use

• Fast development of resistance if adherence is low

• Treatment failure likely if adherence is low

• High incidence of toxicities

• Waste of financial resources

Rational Prescribing

  1. Correct diagnosis
  2. Therapeutic objective
    1. Curative
    1. Symptomatic
    1. Diagnostic
    1. Palliative
  3. STEP criteria


Tolerability – check for C/I , route of administration, dose adjustment if co-morbidities +


Price – available at least cost

  • Actual prescription
  • Verbal instructions to pt
    • How to take the drug
    • Explain s/e- e.g if patient is prescribed metronidazole – avoid alcohol – disulfiram like reaction
    • Explain follow up and why it is necessary
    • Explain whether this treatment is curative or symptomatic
    • Non- pharmacological t/t

P drug

The drugs you are going to prescribe regularly and with which you will become familiar are called P(ersonal)-drugs. The P-drug concept includes the name of a drug, dosage form, dosage schedule and duration of treatment for a specified condition.

The process of choosing a P-drug can be divided into five steps:

  • Define the diagnosis
  • Specify the therapeutic objective
  • Make an inventory of effective groups of drugs
  • Choose an effective group according to criteria
  • Choose a P-drug

1 thoughts on “Rational Use of Drugs

  1. Luke Biete says:

    I found the content very helpful and current to the issues relating to toipic of rational drug use. I would be glad to be receiving updates in this area

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